The present invention relates to an immunoassay for phthalic acid esters.
Phthalic acid esters are chemicals widely used as plasticizers in the manufacturing of plastic products.
Recently, it has been confirmed that phthalic acid esters disrupt the endocrinal system of living organisms, and the leaching phthalic acid esters from plastic products has been recognized as a serious environmental pollution problem.
So far the detection and measurement of phthalic acid esters have been carried out by high performance liquid chromatography, LC-Mass spectrometry, GC-Mass spectrometry and like general methods. However, such methods entail high machinery costs and can test only a limited number of samples. Also, their detection and measurement capability is limited. Therefore, the development of a simple, convenient method capable of precisely detecting and measuring phthalic acid esters in a large number of samples has been desired.
An object of the present invention is to solve the prior art problem and provide a simple, convenient detection and measurement method for phthalic acid esters and means for the detection and measurement.
The inventors succeeded in creating an immunoassay system capable of achieving the object and accomplished the present invention.
The present invention provides the following antigens, anti-phthalic acid ester antibodies, biotinylated phthalic acid ester derivatives, and immunoassays for phthalic acid esters utilizing the antibody or the antibody and the biotinylated derivative.
(1) An antigen for the production of an anti-phthalic acid ester antibody, which comprises a conjugate of a carrier protein and a phthalic acid ester derivative represented by the formula 
wherein R1 and R2 may be the same or different and are hydrogen, alkyl, cycloalkyl or phenylalkyl, with the proviso that both of R1 and R2 are not hydrogen; m is an integer from 1 to 5; and Y is amino or carboxyl.
(2) An anti-phthalic acid ester antibody produced using the antigen defined in item (1).
(3) A biotinylated phthalic acid ester derivative represented by the formula 
wherein R1, R2 and m are as defined above and R3 is biotin-(R4)nxe2x80x94NHxe2x80x94 or xe2x80x94COxe2x80x94(R4)nxe2x80x94NHNH-biotin wherein the R4s may be the same or different and are an Arg residue or a Lys residue, and n is an integer from 1 to 3.
(4) A method for assaying phthalic acid esters in a sample by an immunoassay technique, which comprises measuring the phthalic acid esters contained in the sample using the anti-phthalic acid ester antibody defined in item (2).
(5) The method according to item (4) wherein the immunoassay technique utilizes the biotinylated phthalic acid ester derivative of item (3) as a labeled compound.